Discharge aiding agent for petroleum fracturing and application

Abstract

The invention relates to a cleanup additive for petroleum fracturing and application, the cleanup additive comprises 1-8 parts of bactericide, 6 parts of emulsifier, 1-3 parts of inorganic salt, 3-6 parts of quaternary ammonium salt surfactant, 4-6 parts of fatty alcohol-polyoxyethylene ether, 1-2 parts of viscosity modifier, 15-40 parts of water and 5-25 parts of oil, and the oil can be selected from alkane, olefin, aromatic hydrocarbon and fatty ester. The cleanup additive further comprises 1-2 parts of a buffer solution. According to the invention, the bactericide and the surfactant are added, so that the discharge aiding agent can be used as a fracturing fluid bactericide and also can be used as a fracturing discharge aiding agent, the types of assistants in the oil exploitation process can be reduced, and the workload of workers is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical industry, and in particular to a drainage aid for petroleum fracturing and application thereof. Background Art

[0002] In oilfield fracturing and acidizing operations, the well fluid must be quickly and thoroughly discharged from the ground after the operation is completed so as not to cause secondary pollution to the formation and achieve the purpose of increasing production and injection. However, the residual liquid after the operation is often unable to be completely discharged due to the high surface tension. The addition of drainage aids can effectively reduce the surface tension and increase the interfacial activity, which is conducive to the timely return of the well fluid. In addition, adding drainage aids to the well fluid can effectively reduce the interfacial tension, which is conducive to the smooth injection of the well fluid. Usually, the drainage aid is added with various surfactants, which can reduce the surface tension of the well fluid or increase the wetting properties of the well fluid, so as to facilitate the timely return of the well fluid. In practical applications, a variety of additives need to be added to the well fluid. In addition to the drainage aid, a bactericide needs to be added to facilitate the disinfection of various microorganisms in the well to cope with the growth of various microorganisms in a complex environment. This requires the staff to add different additives to the well fluid in multiple times or compound them according to the proportion, which increases the cumbersomeness of the staff's operation. Therefore, developing a product that can act as both a drainage aid and a well fluid sterilizer can reduce the types of additives used in the oil and gas production process, thereby reducing the workload of staff. Summary of the invention

[0003] The present invention provides a drainage aid for petroleum fracturing and application thereof to solve the above problems.

[0004] The technical solution adopted by the present invention is: a drainage aid for petroleum fracturing, which includes 1-8 parts of bactericide, 6 parts of emulsifier, 1-3 parts of inorganic salt, 3-6 parts of quaternary ammonium salt surfactant, 4-6 parts of fatty alcohol polyoxyethylene ether, 1-2 parts of viscosity regulator, 15-40 parts of water, and 5-25 parts of oil, and the oil can be selected from alkanes, olefins, aromatic hydrocarbons, and fatty esters.

[0005] Preferably, the drainage aid further comprises 1-2 parts of a buffer solution.

[0006] Preferably, the method for preparing the bactericide comprises the following steps:

[0007] (1) 10 parts of epichlorohydrin and 13 parts of trimethylamine hydrochloride were added to a reaction kettle, and 40 parts of sodium hydroxide solution were added, and stirred for 2 hours to obtain a 2,3-epoxypropyltrimethylammonium chloride solution;

[0008] (2) placing the chitosan solution in an acetic acid solution, adding a sodium hydroxide solution until the pH value of the solution is 8-10, slowly dripping the 2,3-epoxypropyltrimethylammonium chloride solution prepared in step (1), and irradiating with microwaves at a temperature of 50-75° C. for 30-60 min;

[0009] (3) The product is obtained after purification with acetone, concentration and drying.

[0010] Preferably, the sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass concentration of 30%.

[0011] Preferably, the emulsifier comprises 2 parts of Tween-80, 2 parts of sodium dodecylbenzene sulfonate, and 2 parts of cocamidopropyl betaine.

[0012] Preferably, the oil is a saturated alkane, and the number of carbon chains of the saturated alkane is n, where n is a positive integer of 8-18, and the inorganic salt is selected from one of potassium chloride and sodium chloride.

[0013] Preferably, the drainage aid further comprises 3-5 parts of mesoporous nano-silica microspheres, and the nano-silica microspheres are hollow in structure, and the bactericide, quaternary ammonium salt surfactant, and fatty alcohol polyoxyethylene ether are all loaded on the nano-silica.

[0014] Preferably, the preparation method of the drainage agent comprises the following steps:

[0015] S1: preparing fungicide;

[0016] S2: Mix the nano-silica microspheres with anhydrous ethanol, and ultrasonically disperse them for 50-100 minutes. Add the quaternary ammonium surfactant, fatty alcohol polyoxyethylene ether, and bactericide to the anhydrous ethanol, and add vinyl trimethoxysilane. Stir and react for 30-60 minutes, wherein the mass ratio of vinyl trimethoxysilane to the nano-silica microspheres is 1:(10-15). After filtering and washing, the loaded microspheres are obtained.

[0017] S3: Add emulsifier to water, stir for 2-5 minutes, then add oil, continue stirring for 5-8 minutes, add inorganic salt and buffer solution, continue stirring, add loaded microspheres, stir and let stand.

[0018] Compared with the prior art, the present invention has the following advantages: by adding a bactericide and a surfactant, the drainage aid can be used as both a fracturing fluid bactericide and a fracturing drainage aid, which can reduce the types of additives in the oil production process and reduce the workload of the staff. By adding an emulsifier, water and oil, the drainage aid has an oil phase, a water phase and a microemulsion phase, so that the drainage aid can emulsify the water and oil in the well fluid at the same time, reduce its surface tension, and improve the drainage effect. DETAILED DESCRIPTION

[0019] In order to better illustrate the present invention, it is further described in conjunction with examples.

[0020] A drainage aid for petroleum fracturing, comprising 1-8 parts of a bactericide, 6 parts of an emulsifier, 1-3 parts of an inorganic salt, 3-6 parts of a quaternary ammonium surfactant, 4-6 parts of a fatty alcohol polyoxyethylene ether, 1-2 parts of a viscosity regulator, 15-40 parts of water, 5-25 parts of oils, and 1-2 parts of a buffer solution, wherein the oils can be selected from alkanes, olefins, aromatic hydrocarbons, and fatty esters.

[0021] Preferably, the method for preparing the bactericide comprises the following steps:

[0022] (1) 10 parts of epichlorohydrin and 13 parts of trimethylamine hydrochloride were added to a reaction kettle, and 40 parts of sodium hydroxide solution were added, and stirred for 2 hours to obtain a 2,3-epoxypropyltrimethylammonium chloride solution;

[0023] (2) placing the chitosan solution in an acetic acid solution, adding a sodium hydroxide solution until the pH value of the solution is 8-10, slowly dripping the 2,3-epoxypropyltrimethylammonium chloride solution prepared in step (1), and irradiating with microwaves at a temperature of 50-75° C. for 30-60 min;

[0024] (3) The product is obtained after purification with acetone, concentration and drying.

[0025] Preferably, the sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass concentration of 30%, and the viscosity modifier is a polyurethane thickener and microcrystalline cellulose, and the weight ratio of the two is 1:1.

[0026] Preferably, the emulsifier comprises 2 parts of Tween-80, 2 parts of sodium dodecylbenzene sulfonate, and 2 parts of cocamidopropyl betaine.

[0027] Preferably, the oil is a saturated alkane, and the number of carbon chains of the saturated alkane is n, where n is a positive integer of 8-18, and the inorganic salt is selected from one of potassium chloride and sodium chloride.

[0028] Preferably, the drainage aid further comprises 3-5 parts of mesoporous nano-silica microspheres, and the nano-silica microspheres are hollow in structure, and the bactericide, quaternary ammonium salt surfactant, and fatty alcohol polyoxyethylene ether are all loaded on the nano-silica.

[0029] Preferably, the preparation method of the drainage agent comprises the following steps:

[0030] S1: preparing fungicide;

[0031] S2: Mix the nano-silica microspheres with anhydrous ethanol, and ultrasonically disperse them for 50-100 minutes. Add the quaternary ammonium surfactant, fatty alcohol polyoxyethylene ether, and bactericide to the anhydrous ethanol, and add vinyl trimethoxysilane. Stir and react for 30-60 minutes, wherein the mass ratio of vinyl trimethoxysilane to the nano-silica microspheres is 1:(10-15). After filtering and washing, the loaded microspheres are obtained.

[0032] S3: Add emulsifier to water, stir for 2-5 minutes, then add oil, continue stirring for 5-8 minutes, add inorganic salt and buffer solution, continue stirring, add loaded microspheres, stir and let stand.

[0033] Example 1

[0034] A drainage aid for petroleum fracturing comprises 1 part of bactericide, 2 parts of Tween-80, 2 parts of sodium dodecylbenzene sulfonate, 2 parts of cocamidopropyl betaine, 1 part of sodium chloride, 3 parts of quaternary ammonium salt surfactant, 6 parts of fatty alcohol polyoxyethylene ether, 1 part of polyurethane thickener, 1 part of microcrystalline cellulose, 15 parts of water, 5 parts of octane, 1 part of Tris buffer solution, and 3 parts of mesoporous nano-silica microspheres. The nano-silica microspheres are of a hollow structure, and the bactericide, quaternary ammonium salt surfactant, and fatty alcohol polyoxyethylene ether are all loaded on the nano-silica.

[0035] The preparation method of the fungicide comprises the following steps:

[0036] (1) 10 parts of epichlorohydrin and 13 parts of trimethylamine hydrochloride are added to a reaction kettle, and 40 parts of sodium hydroxide solution are added, and stirred for 2 hours to obtain 2,3-epoxypropyltrimethylammonium chloride solution; (2) chitosan solution is added to acetic acid solution, and sodium hydroxide solution is added until the pH value of the solution is 8-10, and the 2,3-epoxypropyltrimethylammonium chloride solution prepared in step (1) is slowly dripped into it, and microwave irradiated for 30-60 minutes at a temperature of 50-75°C; (3) the product is obtained after purification with acetone, concentration and drying. Wherein, the sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass concentration of 30%.

[0037] The preparation method of the drainage agent comprises the following steps:

[0038] S1: preparing fungicide;

[0039] S2: Mix the nano-silica microspheres with anhydrous ethanol, and ultrasonically disperse them for 50-100 minutes. Add the quaternary ammonium surfactant, fatty alcohol polyoxyethylene ether, and bactericide to the anhydrous ethanol, and add vinyl trimethoxysilane. Stir and react for 30-60 minutes, wherein the mass ratio of vinyl trimethoxysilane to the nano-silica microspheres is 1:(10-15). After filtering and washing, the loaded microspheres are obtained.

[0040] S3: Add emulsifier to water, stir for 2-5 minutes, then add oil, continue stirring for 5-8 minutes, add inorganic salt and buffer solution, continue stirring, add loaded microspheres, stir and let stand.

[0041] Example 2

[0042] A drainage aid for petroleum fracturing comprises 6 parts of bactericide, 2 parts of Tween-80, 2 parts of sodium dodecylbenzene sulfonate, 2 parts of cocamidopropyl betaine, 2 parts of potassium chloride, 5 parts of quaternary ammonium salt surfactant, 5 parts of fatty alcohol polyoxyethylene ether, 1 part of polyurethane thickener, 1 part of microcrystalline cellulose, 30 parts of water, 15 parts of tetradecane, 1.5 parts of Tris buffer solution, and 4 parts of mesoporous nano-silica microspheres. The nano-silica microspheres are of a hollow structure, and the bactericide, quaternary ammonium salt surfactant, and fatty alcohol polyoxyethylene ether are all loaded on the nano-silica.

[0043] The preparation method of the fungicide comprises the following steps:

[0044] (1) 10 parts of epichlorohydrin and 13 parts of trimethylamine hydrochloride are added to a reaction kettle, and 40 parts of sodium hydroxide solution are added, and stirred for 2 hours to obtain 2,3-epoxypropyltrimethylammonium chloride solution; (2) chitosan solution is added to acetic acid solution, and sodium hydroxide solution is added until the pH value of the solution is 8-10, and the 2,3-epoxypropyltrimethylammonium chloride solution prepared in step (1) is slowly dripped into it, and microwave irradiated for 30-60 minutes at a temperature of 50-75°C; (3) the product is obtained after purification with acetone, concentration and drying. Wherein, the sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass concentration of 30%.

[0045] The preparation method of the drainage agent comprises the following steps:

[0046] S1: preparing fungicide;

[0047] S2: Mix the nano-silica microspheres with anhydrous ethanol, and ultrasonically disperse them for 50-100 minutes. Add the quaternary ammonium surfactant, fatty alcohol polyoxyethylene ether, and bactericide to the anhydrous ethanol, and add vinyl trimethoxysilane. Stir and react for 30-60 minutes, wherein the mass ratio of vinyl trimethoxysilane to the nano-silica microspheres is 1:(10-15). After filtering and washing, the loaded microspheres are obtained.

[0048] S3: Add emulsifier to water, stir for 2-5 minutes, then add oil, continue stirring for 5-8 minutes, add inorganic salt and buffer solution, continue stirring, add loaded microspheres, stir and let stand.

[0049] Example 3

[0050] A drainage aid for petroleum fracturing comprises 8 parts of bactericide, 2 parts of Tween-80, 2 parts of sodium dodecylbenzene sulfonate, 2 parts of cocamidopropyl betaine, 3 parts of sodium chloride, 6 parts of quaternary ammonium salt surfactant, 4 parts of fatty alcohol polyoxyethylene ether, 1 part of polyurethane thickener, 1 part of microcrystalline cellulose, 40 parts of water, 25 parts of octadecane, 2 parts of Tris buffer solution, and 5 parts of mesoporous nano-silica microspheres. The nano-silica microspheres are of a hollow structure, and the bactericide, quaternary ammonium salt surfactant, and fatty alcohol polyoxyethylene ether are all loaded on the nano-silica.

[0051] The preparation method of the fungicide comprises the following steps:

[0052] (1) 10 parts of epichlorohydrin and 13 parts of trimethylamine hydrochloride are added to a reaction kettle, and 40 parts of sodium hydroxide solution are added, and stirred for 2 hours to obtain 2,3-epoxypropyltrimethylammonium chloride solution; (2) chitosan solution is added to acetic acid solution, and sodium hydroxide solution is added until the pH value of the solution is 8-10, and the 2,3-epoxypropyltrimethylammonium chloride solution prepared in step (1) is slowly dripped into it, and microwave irradiated for 30-60 minutes at a temperature of 50-75°C; (3) the product is obtained after purification with acetone, concentration and drying. Wherein, the sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass concentration of 30%.

[0053] The preparation method of the drainage agent comprises the following steps:

[0054] S1: preparing fungicide;

[0055] S2: Mix the nano-silica microspheres with anhydrous ethanol, and ultrasonically disperse them for 50-100 minutes. Add the quaternary ammonium surfactant, fatty alcohol polyoxyethylene ether, and bactericide to the anhydrous ethanol, and add vinyl trimethoxysilane. Stir and react for 30-60 minutes, wherein the mass ratio of vinyl trimethoxysilane to the nano-silica microspheres is 1:(10-15). After filtering and washing, the loaded microspheres are obtained.

[0056] S3: Add emulsifier to water, stir for 2-5 minutes, then add oil, continue stirring for 5-8 minutes, add inorganic salt and buffer solution, continue stirring, add loaded microspheres, stir and let stand.

[0057] Test and evaluation of bactericidal effect

[0058] Take the untreated oil-water mixture of an oil field, add fungicides of different concentrations, put it in a 40℃ oven, take samples after 1 hour, detect the number of SRB and TGB after dilution, and calculate the bactericidal rate. The test results are shown in Table 1, among which the control example is dodecyl dimethyl benzyl ammonium chloride.

[0059] Table 1 Bactericidal effect

[0060]

[0061] The above-described embodiments are only preferred embodiments of the present invention. It should be noted that those skilled in the art may make several changes and improvements without departing from the overall concept of the present invention, and these should also be regarded as within the scope of protection of the present invention.

Claims

1. A drainage agent for oil fracturing, characterized in that: The drainage aid comprises 1-8 parts of a fungicide, 6 parts of an emulsifier, 1-3 parts of an inorganic salt, 3-6 parts of a quaternary ammonium surfactant, 4-6 parts of a fatty alcohol polyoxyethylene ether, 1-2 parts of a viscosity regulator, 15-40 parts of water, and 5-25 parts of oils, wherein the oils can be selected from alkanes, olefins, aromatic hydrocarbons, and fatty esters.

2. The oil fracturing agent according to claim 1, characterized in that: The drainage aid also includes 1-2 parts of buffer solution.

3. The oil fracturing drainage agent according to claim 1, characterized in that: The preparation method of the bactericide comprises the following steps: (1) Take 10 parts of epichlorohydrin and 13 parts of trimethylamine hydrochloride, add them into a reaction kettle, add 40 parts of sodium hydroxide solution, and stir for 2 hours to obtain 2,3-epoxypropyltrimethylammonium chloride solution; (2) Place chitosan solution in acetic acid solution, add sodium hydroxide solution until the pH value of the solution is 8-10, slowly drop the 2,3-epoxypropyltrimethylammonium chloride solution prepared in step (1), and irradiate with microwaves at a temperature of 50-75°C for 30-60 minutes; (3) After purification with acetone, concentration and drying, the product is obtained.

4. The oil fracturing drainage agent according to claim 3, characterized in that: The sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass concentration of 30%.

5. The oil fracturing drainage agent according to claim 4, characterized in that: The emulsifier comprises 2 parts of Tween-80, 2 parts of sodium dodecylbenzene sulfonate and 2 parts of cocamidopropyl betaine.

6. The oil fracturing drainage agent according to claim 1, characterized in that: The oil is a saturated alkane, and the number of carbon chains of the saturated alkane is n, where n is a positive integer of 8-18. The inorganic salt is selected from one of potassium chloride and sodium chloride.

7. The oil fracturing drainage agent according to claim 1, characterized in that: The drainage aid also includes 3-5 parts of mesoporous nano-silicon dioxide microspheres, and the nano-silicon dioxide microspheres are hollow in structure. The bactericide, quaternary ammonium salt surfactant and fatty alcohol polyoxyethylene ether are all loaded on the nano-silicon dioxide.

8. The oil fracturing drainage agent according to claim 7, characterized in that: The preparation method of the drainage agent comprises the following steps: S1: preparing fungicide; S2: Mix the nano-silica microspheres with anhydrous ethanol, and ultrasonically disperse them for 50-100 minutes. Add the quaternary ammonium surfactant, fatty alcohol polyoxyethylene ether, and bactericide to the anhydrous ethanol, and add vinyl trimethoxysilane. Stir and react for 30-60 minutes, wherein the mass ratio of vinyl trimethoxysilane to the nano-silica microspheres is 1:(10-15). After filtering and washing, the loaded microspheres are obtained. S3: Add emulsifier to water, stir for 2-5 minutes, then add oil, continue stirring for 5-8 minutes, add inorganic salt and buffer solution, continue stirring, add loaded microspheres, stir and let stand.

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